The present invention relates to an effect imparting apparatus for changing or controlling sound image localization states of multi-channel audio signals arranged to achieve sound image localization in two dimensions (in a two-dimensional plane).
In the field of tone generators and mixers, one-dimensional sound-image-localizing panning control has been conventionally performed to control sound volume balance between left (L) and right (R) channels in accordance with operated amounts of predetermined panning operators. It has also been conventionally known to perform automatic panning control which automatically pans (i.e., moves) sound image localization (here, sound-image-localized position or sound image position) of left and right channels by controlling sound volume balance between left and right channels in accordance with a low-frequency waveform generated by a low-frequency oscillator (LFO) rather than in accordance with user's operation of predetermined panning operators. Further, a 5.1-channel surround mode is often employed these days, and it has also been proposed to perform multi-channel panning (see Japanese Patent Laid-open Publication No. HEI-11-46400). For example, to perform panning for 5.1 channels, coordinates in a two-dimensional plane are designated, for each input channel, in response to user operation of respective operators so that sound volume balance among audio signals to be output from the input channel to five mixing buses (i.e., left (L), right (R), center (C), left rear (LS) and right rear (RS)) is controlled in accordance with the designated 5.1-channel coordinates. However, the conventional 5.1-channel sound image panning control is extremely complicated and troublesome because the panning control is performed in a signal source that generates multi-channel audio signals.
Today, with widespread use of DVDs (Digital Versatile Disks), it has become common to handle multi-channel audio signals of the 5.1-channel surround mode. Such surround-mode multi-channel audio signals are imparted in advance with given two-dimensional sound image localization. However, hitherto, there has been no effect imparting apparatus which can input thereto multi-channel audio signals, such as those of the 5.-1 channel surround mode, and easily impart the input audio signals with an effect to pan or change the original two-dimensional sound image localization of the audio signals.